pdfwak {lmomco} | R Documentation

## Probability Density Function of the Wakeby Distribution

### Description

This function computes the probability density of the Wakeby distribution given parameters (xi, α, β, gamma, and delta) of the distribution computed by `pargev`. The probability density function of the distribution is

f(x) = [α(1-F)^{β - 1} + gamma(1-F)^{-delta - 1}]^-1mbox{,}

where f(x) is the probability density for quantile x,xi is a location parameter, α and β are scale parameters, and gamma, and delta are shape parameters. The five returned parameters from `parwak` in order are xi, α, β, gamma, and delta.

### Usage

    pdfwak(x, para)

### Arguments

`x` | A real value.
`para` | The parameters from `parwak` or similar.

### Value

Probability density (f) for x.

### Author(s)

W.H. Asquith

### References

Hosking, J.R.M. and Wallis, J.R., 1997, Regional frequency analysis—An approach based on L-moments: Cambridge University Press.

Sourced from written communication with Dr. Hosking in October 2007.

### See Also

`cdfwak`, `quawak`, `parwak`

### Examples

    lmr <- vec2lmom(c(1,0.5,.4,.3,.15))
    wak <- parwak(lmr)
    F <- nonexceeds()
    x <- quawak(F,wak)
    check.pdf(pdfwak,wak,plot=TRUE)

[Package lmomco version 0.92 Index]